Abrasive throwing machine



Aug. 29, 1939. v. E. MINICH Y ABRASIVE THROWING MACHINE INV ENTQR Vern!Eflmu/i {Iiiya/lirlll!llirrll Driginal Filed May 25, 1934 K L ATTORNEYSPatented Aug. 29, 1939 UNITED STATES PATENT OFFICE 2,170,832 snaasrva'rnnowmc 'mcnmn Original application May 25, 1934, Serial No.

Divided and this application November 11, 1935, Serial No. 49,328.Renewed April 10 Claims.

This invention relates to abrasive throwing machines and moreparticularly to apparatus for directing and controlling the abrasivethrown by themachine.

This application is a division oi my copending application, Serial No.727,398, filed May 25, 1934.

This invention comprehends the provision of devices adapted to beassociated with an abrasive throwing machine whereby the abrasive thrownmay be controlled particularly as respects to the direction of flight;area covered by. the thrown abrasive, and intensity of impingement. Themachine generally comprises spaced rotatably mounted discs havingremovable and replaceable throwing blades radially arrangedtherebetween. The blades are preferably shaped to contain the abrasiveentirely within the area of the blade and out of wearing contact withthe permanent parts of the machine. The blades preferably extend shortof the center of the machine so as to provide a center inlet throughwhich the abrasive feeding means may be inserted. The abrasive may beconveyed to the machine through a suitable feed pipe in which theabrasive is moved either by gravity, air blast, screw conveyor or othermeans. A discharge nozzle is adjustably connected to the end of the feedpipe, extends into the center inlet and directs the abrasivesubstantially radially across the inner ends of the throwing blades.

The direction in which the abrasive is thrown from the machine dependsupon the point at which the abrasive is fed into the path of therotating throwing blades. By adjusting the position bf the dischargeopening of the feed nozzle the abrasive may be thrown in any desireddirection. The length of the path swept by the thrown abrasive isdetermined by the peripheral length of the discharge opening in the reednozzle. Means are provided for adjusting the peripheral length of thedischarge opening in the feed noz zle, and thereby controlling andregulating the length of the path swept by the thrown abrasive.

The intensity of abrasive impingement against the work is determined bythe peripheral length ing blades. The control devices may be adjusted toadapt the machine to a variety of difierent operating conditions.

An object of this invention is to provide means by which thrown abrasivemay be directionally controlled so that the desired workarea will beimpinged thereby.

Another object of this invention is to provide means whereby the areacovered by the thrown abrasive may be regulated and controlled.

Still. another object of this invention is to provide means forregulating and controlling the intensity of impingement of the thrownabrasive.

Another object of this invention is to provide an abrasive throwingmachine adapted to be adjusted to effectively clean and abrade undervarying operating conditions articles and objects which vary in shape,hardness and surface characteristics.

Another object of this invention is to provide an abrasive throwingmachine which is simple in construction, which .has a low powerconsumption for the work done, which imparts to. the abrasive a highlyefiective abrasive velocity, which causes a minimum disintegration ofthe abrasive particles, which is durable and lasting in construction,which is not subjected to excessive wear from the abrasive when thrownfrom the machine, and which is highly effective for the cleaning ofmetal sheets, billets, castings, forgings and other metallic objects.

Other objects of this invention will become apparent as the disclosureproceeds. In order that a clearer understanding of my invention may behad, attention is hereby directed to the drawing forming a part of thisapplication, and illustrating certain possible embodiments of myinvention.

Referring to the drawing:

Fig. 1 is a longitudinal cross sectional view through an abrasivethrowing machine having associated therewith a feed control device, thisview being taken on line l-l of Fig. 2;

Fig. 2 is a transverse cross sectional view through the machine shown inFig. 1, this view being taken on line 2-2 of Fig. 1;

Fig. 3 is a fragmentary top view of the abrasive sive control deviceshown in Fig. 5. certain parts being broken away tomore clearlyillustrate the construction; and

Fig. '7 is a transverse cross sectional viewthe abrasive throwingmachine comprises the spaced plates or discs I and 2 joined together byradially extending vanes 3. The rotor is suitably mounted upon a shaft(not shown) which is fixed to the hub extending from the disc I, seeFig. 2. Removable and replaceable wear plates or shoes 17 of generallychannel form rest upon the vanes 3 and may be held in position by meansof set screws 6 which extend through the plate 2 and engage with thesides of the removable blades. Any well known means, however, forsecuring the throwing blades in position may be used within thecontemplation of this invention. The radial supporting vanes 3 and thethrowing blades b extend short of the center of the rotor providing anopen chamber or center inlet 0 centrally of the machine. It isunderstood that the side wall plates and 2 shown in Figs. 1 and 2 aregenerally circular in shape and the supporting vanes 3 and blades b aresubstantially similar in shape and size, so that the lower portion ofthe machine, as shown in Figs; 1 and 2, is substantially a duplicate ofthe upper portion of the machine as shown in Figs. 1 and 2.

A feeding device is provided which extends through an opening 40 cutthrough the center of the disc 2 and extends into the center inlet '0.The feeding device comprises a feed pipe I which conducts the abrasiveto a feed nozzle l| adJustably mounted on the end of the pipe I. A screwconveyor, see Fig. 7, comprising the helical vane 8 supported by thecore 9 may be used to move the abrasive through the pipe I. A.

spider it may be fixed within theendof pipe 'I to rotatably support thecore 9 of the screw conveyor. Other means for feeding theabrasive intothe feed nozzle H such as air blast, gravity, or. both may also be'usedwithin the contemplation of this invention.

The feed nozzle II is provided with a discharge opening in the endthereof which is positioned adjacent to the inner ends of throwingblades b. The axial width of the discharge open-* ing is not greater andpreferably less than the axial width of the throwing blades b\and is soshaped as to direct the abrasive into the chanwith a flanged portion itwhich extends around the collar portion ii of the feed pipe I andretains the feed nozzle II in position. A set screw extending throughthe flange portion It and engaging the collar portion It, may be used toretain the feed nozzle H in any desired adjusted position. Other. meansfor adiustably securing the feed nozzle ii to the end of the feed pipe'Imaybeused.

A throwing machine having a diameter of approximately 20 inches androtated at approximately' 2,200 revolutions per minute will effectivelyabrade and clean metallic castings, forge ings, billets, metal sheetsand other metallic objects. When the discharge opening of the feednozzle II is positioned at approximately the 12 o'clock position, arotor 20 inches in diameter operating at 2,200 revolutions per minutewill discharge the abrasive from approximately the 4 o'clock to the 8o'clock position. With a given machine rotated at a specified R. P. M.the direction of discharge will be determined by the position of thedischarge opening of the feed nozzle. The abrasive can, therefore, bethrown in any desired direction by swinging the nozzle around to theproper position and securing the same in this position by means of theset screw The discharge end of the feed nozzle H is fixed so as todirect the abrasive substantially radially across the inner ends it ofthe throwing blades b thus injecting the abrasive into the path of themoving blades when rotating at a high velocity.

The length of the path swept by the thrown abrasive is determined by theperipheral length of the discharge opening of the feed nozzle. With adischarge opening of fixed peripheral length, the path swept by thethrown abrasive will be substantially uniform in machines of the samediameter rotating at approximately the same speeds. With a givendischarge opening the intensity of impingement depends upon the amountof abrasive fed through the machine per minute. The length of the pathswept by the thrown abrasive can be varied in a given machine bychanging the peripheral length of the discharge opening in the feednozzle. The machine shown in Figs. 1, 2 and 3 is equipped with a feednozzle the discharge opening of which may be varied in peripherallength. The feed nozzle H as shown comprises a neck portion 4| havingspaced V-shaped side wall plates 20 and 2| extending at right anglesthereto. One end of the V-shaped plates 20 and 2| are joined by an endwall 22 and abottom. :wall 23, The other end of the nozzle is closed bya movable end wall 24 suitably hinged by a rivet 28 to one of the sidewalls .2| of the nozzle. As illustrated more particularly in Fig. 4, theperipheral length of the discharge opening of the feed nozzle may bevaried by swinging the end wall 24 in an arc. ,The peripheral length ofthe discharge opening in the nozzle may thus be varied from a maximumequal substantially to the peripheral width of the side plates 20 and 2|to a minimum in which the end wall 22 and movable end wall 24 aresubstantially in abutment. The size of the intake end of the nozzleremains substantially unchanged at all times. If desired, both the endwalls 22 and 24 may be made movable in an arc.

Means are provided for retaining the movable end wall 24 in any desiredadjusted position. The end wall 24 may be provided with a top flangeportion 25 which extends away'from the dis-' charge opening so as to notinterfere with the abrasive discharge. The flange portion 25 is providedwith a downturned lip portion 21 which overhangs the side wall 20 of thenozzle. A

threaded set screw 26 or other device extends through the lip portion 21and frictionally engages the side wall 2|! of the nozzle so as toreleasably retain the end wall 24 of the nozzle in any desired adjustedposition.

The discharge opening in the nozzle may be moved into, any positionwithin the center inlet 0 'so as to direct the abrasive against the worksurface. The nozzle is retained in the desired adjusted position bymanipulating the set screw I! which secures the nozzle II to the feedpipe 1. Either a screw conveyor, gravity, low pressure air blast, or acombination of one or more of these may be used to force the abrasivethrough the discharge opening in the nozzle. With the V-shaped type ofnozzle it is sometimes desirable to use a combination of gravity orconveyor and air blast feed, such as illustrated more particularly inFig. '7. This will be described more fully hereinafter. g

There is shown in Figs. 5, 6 and 7 a modified form of V-shaped dischargenozzle in which the size and peripheral length of the discharge openingis varied as desired by means of one or more sliding shutters 3| whichmay be moved teenlarge or reduce the size of the discharge opening. Theshutters 3| may be slidably retaineddn position by the provision ofrolled edge portions 34 which slidably grip rim portions 33 extendingoutwardly from the top edge of the side walls 20 and 2|. A suitablehandle 32 may be provided for,v manipulating the sliding shutters 3|.The nozzle may be provided with fixed end walls 22 and or the end wallsmay be made movable in an are in' the manner illustrated in Fig. 4. Thelength of path swept by the thrown abrasive may be regulated byadjusting the sliding shutters 3| into the proper position. Directionalcontrol of the thrown abrasive may also be effected by swinging thedischarge end of the nozzle into the proper position and securing thesame inthis position by means of the adjusting screw ll. When this typeof nozzle is used, the direction of flight of the thrown abrasive, aswell as the length of path swept by the abrasive, may be varied asdesired without requiring a change of nozzles.

Where a V-shaped nozzle is used, it may be advisable under certainoperating conditions to augment the conveyor or gravity feed by a lowpressure stream of -air. As illustrated in Fig. 7, the discharge end 36of the air pipe 35 extends through the bottom portion 23 of the nozzle.A screw conveyor or gravity is used to carry the abrasive to the nozzle,at which point the air blast emitted from the discharge end 36 of theair pipe 35 blows the abrasive through the nozzle and distributes theabrasive so as to obtain a substantially uniform intensity of dischargethroughout the cross-sectional area of the nozzle discharge opening. Thedischarge end 36 of the air pipe is so shaped to effectuate this result.

with a machine as above constructed the abrasive can be thrown in anydesired direction so as to impinge the desired work area and performeffective work. The direction of discharge is conchange the lengthofpath swept by the abrasive 76 at intervals, a feed nozzle having anadjustable abrasive.

discharge opening, such as shown in the figures. may be preferable. Theabrasive may be propelled through the feed nozzle by means of gravity,conveyor, low air blast, or a combination of one or more of these. Thedischarge opening in the air nozzle is preferably so arranged as todirect the abrasive substantially radially across the inner ends of theblades. All of the abrasive fed into the machine is thus directed intothe path of the moving blades and swirling of the abrasive within andaround the machine is prevented. The axial width of the dischargeopening is no greater and preferably less than the width of the throwingblade and is so shaped as to direct all of the abrasive within theconflne's of the removable throwing blade and out of contact with thepermanent side plates 1 and 2 of the machine.

' annexed claims, it will be understood that various omissions,substitutions and changes may be made by those skilled in the artwithout departing fromv the spirit of the invention.

What is claimed is:

1. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throwing bladesextending inwardly'short of the axis of rotation of said blades toprovide a center inlet. abrasive feeding means including an elbow-shapednozzle having a discharge opening extending into said center inletoperative to direct abrasive into the path of rotation of said bladesfor a limited arc, and means for controlling the length of path swept bythe thrown abrasive including, a movable element associated with saidelbow-shaped nozzle for adjusting the peripheral length of saiddischarge opening.

2. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throwing bladesextending inwardly short of the axis of rotation of said blades toprovide a center inlet, abrasive feeding means including an elbow-shapednozzle having a discharge opening extending into said center inletoperative to direct the abrasive substantially radially into the path ofrotation of said blades over a limited arc, and movable means associatedwith said nozzle opening for adjusting the circumferential length ofsaid opening thereby regulating the length of path swept by the thrown3. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throwing bladesextending inwardly short of the axis of rotation of said blades toprovide a center inlet, abrasive feeding means including a feed pipeconducting the abrasive to said center inlet, and means for controllingthe length of path swept by the thrown abrasive, said means comprisingafeed nozzle arranged to receive the abrasive delivered thereto by saidfeed pipe, said feed nozzle extending into said center inlet having thedischarge end thereof positioned to direct the abrasive substantiallyradially across the inner ends of the moving blades, and adjustablymovable pivotally mounted means forming a side wall for said nozzle andoperative upon adjustment to define the peripheral length of saiddischarge opening.

4. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throwing bladesextending inwardly short of the axis of 7 rotation of said. blades toprovide a center inlet. abrasive feeding means including a feed pipeconducting the-abrasive tosaid center inlet, and means for receiving theabrasive from said feed pipe and controlling the length of path swept bythe abrasive, said means comprising a V-shaped feed nozzle within saidcenter inlet having the discharge end thereof positioned to direct theabrasive substantially radially across the inner ends of the movingblades, and a movable end wall associated with said nozzle forincreasing and decreasing the peripheral length of the discharge openingtherein. a

5. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throwing bladesextending inwardly short of the an; of rotation of said blades toprovide a center inlet, abrasive feeding means including a feed pipeconducting the abrasive to said center inlet, and means for controllingthe length oi path swept by the thrown abrasive, said means comprising afeed nozzle adiustably connected to said feed-pipe and extending intosaid center inlet having the discharge end thereof positioned to directthe abrasive substantially radially across the inner ends of the movingblades, and adjustable shutters fixed to said nozzle but adJustablymovable for increasing and decreasing the peripheral length of thedischarge opening. v

6. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throwing bladesextending inwardly short of the axis of rotation of said blades toprovide a center inlet, abrasive feeding means including a feed pipe, anozzle positioned within said center inlet and adjustably mounted onsaid feed pipe for directing the abrasive discharge, means for forcingthe abrasive through said nozzle and into the path of movement of saidthrowing blades, and adjustably movable shutters for increasing anddecreasing the peripheral length of the discharge opening.

7. In a centrifugal blasting machine designed for throwing abrasive atblasting velocities comprising, spaced rotatably mounted throg bladesextending inwardly short of the of rotation of said blades to provide acenter inlet,

'abrasive. feeding means including a f nozzle at right angles to saidconduit portion, said bend portion having a discharge I t extending intosaid cenizzr inlet and operative to direct the abrasive substantiallyradially across the inner ends of saidblades as they successively pass apredetermined point, and adjustably movable means for increasing anddecreasing the peripheral length of said discharge opening.

8. A centrifugal blasting machine for throwing abrasive at blastingvelocities comprising, a rotor mounted for high speed rotation includingspaced throwing blades extending inwardly toward the axis of rotation ofsaid rotor, an abrasive supply pipe, and a feed nozzle connected to saidabrasive supply pipe having guide walls for conducting the abrasivesubstantially radially of said blades and onto the inner ends of saidblades as they successively pass a predetermined point during rotation,said nozzle being provided with a pivotally mounted movable wall foradjusting the circumferenti'al length of said opening thereby regulatingthe length of path swept by the thrown abrasive.

9. A centrifugal blasting machine for throwing abrasive at blastingvelocities comprising, a rotor mounted for high speed rotation includingspaced throwing blades extending inwardly toward the axis of rotation ofsaid rotor, an abrasive supply pipe, and a feed nozzle connected to saidabrasive supply pipe having guide walls for conducting the abrasivesubstantially radially of said blades and onto the inner ends of saidblades as they successively pass a predetermined point during rotation,said nozzle including side wall members constituting the terminalportion thereof and defining a discharge opening, and means hingedlyconmeeting said side wall members whereby the distance between the endsthereof can be adjusted to vary the size of the discharge opening.

10. A centrifugal blasting machine for throwing abrasive at blastingvelocities comprising, a rotor mounted for high speed rotation includingspaced throwing blades extending inwardly toward the axis of rotation ofsaid rotor, an abrasive supply pipe, and a feed nozzle connected to saidabrasive supply pipe having guide walls for conducting the abrasivesubstantially radially of said blades and onto the inner ends of saidblades as they successively pass a predetermined point during rotation,said nozzle including side walls defining a discharge opening, a shutteradapted to vary the size oi said discharge opening, and means mountingsaid shutter for sliding movement on the end of said nozzle.

VERNE E. lmNICH.

